Dexamethasone released from cochlear implant coatings combined with a protein repellent hydrogel layer inhibits fibroblast proliferation

TY - JOUR

T1 - Dexamethasone released from cochlear implant coatings combined with a protein repellent hydrogel layer inhibits fibroblast proliferation

AU - Wrzeszcz, Antonina

AU - Dittrich, Barbara

AU - Haamann, Daniel

AU - Aliuos, Pooyan

AU - Klee, Doris

AU - Nolte, Ingo

AU - Lenarz, Thomas

AU - Reuter, Günter

N1 - © 2013 Wiley Periodicals, Inc.

PY - 2014/2

Y1 - 2014/2

N2 - The insertion of cochlear implants into the inner ear often causes inflammation and fibrosis inside the scala tympani and thus growth of fibrous tissue on the implant surface. This deposition leads to the loss of function in both electrical and laser-based implants. The design of this study was to realize fibroblast growth inhibition by dexamethasone (Dex) released from the base material of the implant [polydimethylsiloxane (PDMS)]. To prevent cell and protein adhesion, the PDMS was coated with a hydrogel layer [star-shaped polyethylene glycol prepolymer (sPEG)]. Drug release rates were studied over 3 months, and surface characterization was performed. It was observed that the hydrogel slightly smoothened the surface roughened by the Dex crystals. The hydrogel coating reduced and prolonged the release of the drug over several months. Unmodified, sPEG-coated, Dex-loaded, and Dex/sPEG-equipped PDMS filaments were cocultivated in vitro with fluorescent fibroblasts, analyzed by fluorescent microscopy, and quantified by cell counting. Compared to the unmodified PDMS, cell growth on all modified filaments was averagely 95% ±standard deviation (SD) less, while cell growth on the bottom of the culture dishes containing Dex-loaded filaments was reduced by 70% ±SD. Both, Dex and sPEG prevented direct cell growth on the filament surfaces, while drug delivery was maintained for the duration of several months.

AB - The insertion of cochlear implants into the inner ear often causes inflammation and fibrosis inside the scala tympani and thus growth of fibrous tissue on the implant surface. This deposition leads to the loss of function in both electrical and laser-based implants. The design of this study was to realize fibroblast growth inhibition by dexamethasone (Dex) released from the base material of the implant [polydimethylsiloxane (PDMS)]. To prevent cell and protein adhesion, the PDMS was coated with a hydrogel layer [star-shaped polyethylene glycol prepolymer (sPEG)]. Drug release rates were studied over 3 months, and surface characterization was performed. It was observed that the hydrogel slightly smoothened the surface roughened by the Dex crystals. The hydrogel coating reduced and prolonged the release of the drug over several months. Unmodified, sPEG-coated, Dex-loaded, and Dex/sPEG-equipped PDMS filaments were cocultivated in vitro with fluorescent fibroblasts, analyzed by fluorescent microscopy, and quantified by cell counting. Compared to the unmodified PDMS, cell growth on all modified filaments was averagely 95% ±standard deviation (SD) less, while cell growth on the bottom of the culture dishes containing Dex-loaded filaments was reduced by 70% ±SD. Both, Dex and sPEG prevented direct cell growth on the filament surfaces, while drug delivery was maintained for the duration of several months.

KW - Animals

KW - Anti-Inflammatory Agents

KW - Coated Materials, Biocompatible

KW - Cochlear Implants

KW - Delayed-Action Preparations

KW - Dexamethasone

KW - Dimethylpolysiloxanes

KW - Fibroblasts

KW - Hydrogels

KW - Materials Testing

KW - Mice

KW - Nylons

KW - Time Factors

KW - Journal Article

KW - Research Support, Non-U.S. Gov't

U2 - 10.1002/jbm.a.34719

DO - 10.1002/jbm.a.34719

M3 - SCORING: Journal article

C2 - 23533184

VL - 102

SP - 442

EP - 454

JO - J BIOMED MATER RES A

JF - J BIOMED MATER RES A

SN - 1549-3296

IS - 2

ER -